Bumper sub position indicator



l T 5 m 4 0 SEARCH mum 1967 v.0. H. RICHARDSON 3,349,856

BUMPER SUB POSITION INDICATOR Filed Jan. 21, 1966 2 Sheets-Sheet '1 DR/LL/NG PRESSURE U/D TEflMS/JUCH? s g mwmvmw am/A Qgmmm 1L 4 I N V] iN'TUR.

1957 v. c. H. RICHARDSON 3,349,856

- BUMPER SUB POSITION INDICATOR 2 Sheets-Sheet 2 Filed Jan. 2 1966 [N V/iN'I OR.

ATTOQNEYS VERA/0N CH RICHARDSON United States Patent 3,349,856 BUMPER SUB POSITION INDICATOR Vernon C. H. Richardson, Houston, Tex., assignor, by mesne assignments, to the United States of America as represented by the National Science Foundation Filed Jan. 21, 1966, Ser. No. 522,247 4 Claims. (Cl. 175-40) This invention relates generally to apparatus for providing a surface indication when the two telescoping sections of a bumper sub located in a string of drill pipe are in a preselected position relative to each other. In particular, this invention relates to apparatus that provides such surface indication with a pressure signal transmitted to the surface through the drilling fluid being circulated through the pipe string.

It is often desirable to know when a bumper sub in a pipe string is in a preselected position. For example, when the sub is being used to control the weight on a bit, it is desirable to know when the sub is closed. By closed it is meant that the two telescoping sections of the sub have telescoped to the full extent for which the sub is designed and any further lowering of the pipe string will increase the weight on the bit. Conversely, it may be desirable on occasions to know when the sub is fully open, i.e., when the two telescoping sections have moved apart to the extent allowed. When this occurs, the driller can lower the pipe string to prevent the weight on the bit from decreasing as the bit continues to dril. There may also be occasions when it will be desirable to know when the bumper sub is in some preselected position intermedi ate its fully opened and closed position.

Therefore, it is an object of this invention to provide novel apparatus for producing a surface detectable pressure signal in the drilling fluid, being circulated in a string of drill pipe, when a bumper sub in the string is in a preselected position.

It is another object of this invention to provide such apparatus that employs the energy in the drilling fluid to actuate a flow restricting device and create a pressure increase in the drilling fluid that is transmitted to the surface through the drilling fluid.

It is yet another object of this invention to provide such apparatus that employs a flexible sleeve that is collapsed by the pressure differential between the pressure of the drilling fluid upstream of the sleeve and the pressure of the fluid flowing through the sleeve to thereby restrict the flow of fluid through the sleeve and produce an increase in pressure that is transmitted through the drilling fluid to the surface, such sleeve being exposed to the aforesaid differential pressure when the bumper sub is in a preselected position.

These and other objects, advantages, and features of the invention will be apparent to those skilled in the art from a consideration of this specification and attached drawings.

A preferred embodiment of the invention will now be described in detail in connection with the attached drawings in which,

FIGURE 1 is a view, partially schematic and partially in vertical elevation of a string of drill pipe equipped with the apparatus of this invention, a bumper sub, and a drilling bit;

FIGURE 2 is an enlarged view, partially in vertical section and partially in elevation, of the bumper sub and apparatus of this invention in FIGURE 1;

FIGURES 3 and 4 are partial vertical sectional views of the apparatus of this invention and the upper end of the bumper sub of FIGURE 2, the apparatus being shown in FIGURE 3 when the bumper sub is not in the preselected position and in FIGURE 4 when it is and the apparatus is creating a pressure signal in the drilling fluid.

The embodiment of the apparatus shown in the drawings is arranged to indicate at the surface when the bumper sub is closed. Usually, this is the information that is desired, when the bumper sub is employed to maintain a constant weight on the bit.

Therefore, as shown in FIGURE 1, bumper sub 10 is located in the pipe string with a sufficient number of drill collars 11 connected between the bumper sub and bit 12 to provide the desired weight on the bit. Above the bumper sub, additional drill collars can be employed to help maintain drill pipe 13 in tension, or the drill pipe can be connected directly to the top of the bumper sub, as shown in FIGURE 1. With this arrangement, when the bumper sub is between its full open and closed positions, all of the weight of drill collars 11 is supported by the bit. Should pipe string 13 be lowered until the bumper sub is closed however, the weight on the bit can be increased by further lowering of the pipe string. Therefore, it is desirable to know when the bumper sub is closed so that the driller can raise pipe string 13 sufflciently to return the bumper sub to a position between its opened and closed positions.

As shown in FIGURE 2, bumper sub 10 includes first movable section 14 and second movable section 15. The first movable section includes tubular mandrel housing 16 and splines 17, and bottom shoe 19. The splines, only one of which is shown, are located in longitudinal grooves that are spaced around the inner surface of outer mandrel 16 and held in place by machine screws 18 and bottom shoe 19. The splines also extend into grooves provided in the outer surface of mandrel 20, which is a part of the other telescoping section of the bumper sub.

Besides mandrel 20, section 15 also includes outwardly extending annular flange 21 that is integrally attached to mandrel 20 and located to engage the upper end of splines 17 and limit the downward travel of the section relative to the first telescoping section. Section 15 also includes shoulder 22 to engage shoe 19 and limit the extent to which the two sections of the bumper sub can telescope. A seal 23 is located between annular ring 21 and the inner surface of mandrel housing 16 to prevent the escape of drilling fluid from the inside of the bumper sub.

The positioning apparatus of this invention is connected into the pipe string directly above the bumper sub and is indicated generally by the number 30. It includes tubular body 31, which is threadably connected to the upper end of first telescoping section 14 of the bumper sub. The body is provided with a bore of reduced diameter to provide two annular sealing surfaces 32 and 33. The two sealing surfaces are spaced apart axially and encircle the longitudinal axis of the body. For manufacturing convenience, in the embodiment shown, both sealing surfaces are part of a continuous internal bore of the same diameter.

Located in body 31 and in axial alignment therewith is sleeve34. This sleeve is made of a flexible elastomeric material, preferably rubber. It is spaced from the inner surface of body 31 to provide an annular space 35 therebetween. Means are provided to hold the ends of the sleeve open to receive and discharge drilling fluid flowing through the body. In the embodiment shown, rings 36 and 37 of rigid material, preferably steel, are embedded in the opposite ends of sleeve 34 to hold the ends open.

Seal rings are attached to each end of the sleeve to engage the sealing surfaces and alternately close annular space 35. First seal ring 38 is integrally attached to the upper end of sleeve 34 through flange 41 on reinforcing ring 36. The seal ring is located to sealingly engage sealing surface 32 and close the upper end of annular space 35, when sleeve 34 is in the position shown in FIGURE 3. Seal ring 39 is attached to the lower end of sleeve 34 through downwardly extending portion 43 of reinforcing ring 37 as shown. The seal is located to engage surface 33 and close the lower end of annular space 35 when sleeve 34 is moved upwardly by the telescoping of bumper sub 10, in a manner to be described below. Means are provided to hold the ends of the sleeve apart and to space the seal rings axially so that seal ring 39 will be in engagement with seal surface 33 when seal ring 38 moves upwardly out of engagement with seal surface 32. This should occur when the bumper sub is in the preselected position. In the embodiment shown, rigid tubular member 40 is located around the outside of sleeve 34 in annular space 35 between the sleeve and the body. It extends the length of the sleeve and engages flanges 41 and 42 on end reinforcing rings 36 and 37 respectively, to hold the ends of the sleeve apart and to also hold the seal rings properly spaced. Spacer member 49 is provided with a plurality of openings in its wall so the pressure in annular space 35 will be substantially uniform.

When bumper sub is fully open or nearly so, sleeve 34 along with the seal rings and spacer member are held against downward movement by upwardly facing annular shoulder 44 provided on mandrel housing 16 of the bumper sub. The pressure of the downwardly flowing drilling fluid in the drill pipe acting on upper seal 38 will urge the sleeve assembly downwardly, of course, and so some means, such as shoulder 44, should be provided to limit the downward travel of the sleeve assembly. A lower extension member 45 is threadedly connected to portion 43 of ring 37 to engage shoulder 44. This member should be of such length that seal 38 will be in engagement with surface 32 when it is in engagement with the shoulder.

As the bumper sub closes and the two telescoping sections thereof move together, mandrel will move upwardly, engage spacer ring 45, and move the sleeve, seal rings, etc., upwardly relative to body 31. With the sleeve assembly in the position shown in FIGURE 3, annular spacer 35 is open to the pressure of the drilling fluid downstream of the sleeve and the pressures inside and outside of the sleeve will be about equal, so the sleeve will remain in the position shown. As the bumper sub closes, however, seal ring 38 will move out of engagement with seal surface 32 and open up annular space 35 to the pressure of the drilling fluid upstream of the sleeve. concomitantly, with this, seal ring 39 will engage sealing surface 33 and close off annular space 35 to the pressure downstream causing the pressure in the annular space to approach the upstream pressure. Since the drilling fluid will decrease in pressure and increase in velocity as it flows through the sleeve, since there is a reduction of cross sectional area through the sleeve, the pressure inside of sleeve 34 will be less than the pressure in annular space 35. This differential in pressure will cause the sleeve to collapse as shown in FIGURE 4, and cause a sharp increase in pressure in the drilling fluid directly above the sleeve. This increase in pressure will be rapidly transmitted through the drilling fluid to the surface. A pressure transducer or any other appropriate means, can be used to pick up the pressure signal and indicate that the bumper sub is closed. The driller then, of course, can pick up the drill pipe and open the bumper sub. This will permit sleeve 34 and its associated components to return to the position shown in FIGURE 3.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus and structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

1. Apparatus for indicating at the surface when the two telescoping sections of a bumper sub, located in a string of drill pipe through which drilling fluid is pumped, are in a preselected position relative to each other, said apparatus comprising a tubular body adapted to be connected in a drill string for movement with one of the telescoping sections of such bumper sub, said body having first and second internal, axially spaced, annular seal surfaces through which the drilling fluid flows, said seal surfaces encircling the longitudinal axis of the body with the second surface located downstream of the first, a sleeve of flexible, elastomeric material located in the body in axial alignment therewith, said sleeve being spaced from the body to form an annular space therebetween, means for holding the ends of the sleeve open to receive and discharge drilling fluid flowing through the body, means for holding the ends of the sleeve from moving toward each other, first and second seal rings attached to opposite ends of the sleeve for moving into and out of sealing engagement with the first and second seal surfaces respectively as the sleeve moves axially relative to the body, means for spacing the seal rings axially apart sufliciently for only one seal ring to be in sealing engagement with a seal surface at a time whereby one end of the annular space between the sleeve and the body is always open to the pressure of the drilling fluid either upstream or downstream of the sleeve, means for moving the sleeve axially to move the first seal ring out of engagement with the first seal surface and the second seal ring into engagement with the second seal surface to open the annular space between the sleeve and the body to the pressure of the drilling fluid upstream of the first seal surface when the telescoping sections of the bumper sub are in the preselected position, whereby the differential in pressure between the drilling fluid in the annular space and the drilling fluid inside the sleeve will collapse the sleeve and restrict the flow of drilling fluid to produce a pressure pulse that will travel through the drilling fluid to the surface to indicate that the two telescoping sections of the bumper sub are in the preselected position.

2.. The apparatus of claim 1 in which the spacing means is a rigid tubular member located in the annular space between the sleeve and the body and having at least one opening in its walls.

3. The apparatus of claim 1 in which the second seal ring is positioned to be moved into engagement with the second seal surface when the bumper sub to which it is attached is closed.

4. The apparatus of claim 1 further provided with means for holding the first seal in sealing engagement with the first seal surface when the telescoping sections of the bumper sub to which it is connected are not in the preselected position relative to each other.

References Cited UNITED STATES PATENTS 2,783,026 2/1957 Reistle 175325 3,223,184 12/1965 Jones et a1. l243 3,283,823 11/1966 Warrington -243 JAMES A. LE-PPINK, Primary Examiner. 

1. APPARATUS FOR INDICATING AT THE SURFACE WHEN THE TWO TELESCOPING SECTIONS OF A BUMPER SUB, LOCATED IN A STRING OF DRILL PIPE THROUGH WHICH DRILLING FLUID IS PUMPED, ARE IN A PRESELECTED POSITION RELATIVE TO EACH OTHER, SAID APPARATUS COMPRISING A TUBULAR BODY ADAPTED TO BE CONNECTED IN A DRILL STRING FOR MOVEMENTS WITH ONE OF THE TELESCOPING SECTIONS OF SUCH BUMPER SUB, SAID BODY HAVING FIRST AND SECOND INTERNAL, AXIALLY SPACED, ANNULAR SEAL SURFACES THROUGH WHICH THE DRILLING FLUID FLOWS, SAID SEAL SURFACES ENCIRCLING THE LONGITUDINAL AXIS OF THE BODY WITH THE SECOND SURFACE LOCATED DOWNSTREAM OF THE FIRST, A SLEEVE OF FLEXIBLE ELASTOMERIC MATERIAL LOCATED IN THE BODY IN THE AXIAL ALIGNMENT THEREWITH SAID SLEEVE BEING SPACED FROM THE BODY TO FORM AN ANNULAR SPACE THEREBETWEEN, MEANS FOR HOLDING THE ENDS OF THE SLEEVE OPEN TO RECEIVE AND DISCHARGE DRILLING FLUID FLOWING THROUGH THE BODY, MEANS FOR HOLDING THE ENDS OF THE SLEEVE FROM MOVING TOWARD EACH OTHER, FIRST AND SECOND SEAL RINGS ATTACHED TO OPPOSITE ENDS OF THE SLEEVE FOR MOVING INTO AND OUT OF SEALING ENGAGEMENT WITH THE FIRST AND SECOND SEAL SURFACE RESPECTIVELY AS THE SLEEVE MOVES AXIALLY RELATIVE TO THE BODY, MEANS FOR SPACING THE SEAL RINGS AXIALLY APART SUFFICIENTLY FOR ONLY ONE SEAL RING TO BE IN SEALING ENGAGEMENT WITH A SEAL SURFACE AT A TIME WHEREBY ONE END OF THE ANNULAR SPACE BETWEEN THE SLEEVE AND THE BODY IS ALWAYS OPEN TO THE PRESSURE OF THE DRILLING FLUID EITHER UPSTREAM OR DOWNSTREAM OF THE SLEEVE, MEANS FOR MOVING THE SLEEVE AXIALLY TO MOVE THE FIRST SEAL RING OUT OF ENGAGEMENT WITH THE FIRST SEAL SURFACE AND THE SECOND SEAL RING INTO ENGAGEMENT WITH THE SECOND SEAL SURFACE TO OPEN THE ANNULAR SPACE BETWEEN THE SLEEVE AND THE BODY TO THE PRESSURE OF THE DRILLING FLUID UPSTREAM OF THE FIRST SEAL SURFACE WHEN THE TELESCOPING SECTIONS OF THE BUMPER SUB ARE IN THE PRESELECTED POSITION, WHEREBY THE DIFFERENTIAL IN PRESSURE BETWEEN THE DRILLING FLUID IN THE ANNULAR SPACE AND THE DRILLING FLUID INSIDE THE SLEEVE WILL COLLAPSE THE SLEEVE AND RESTRICT THE FLOW OF DRILLING FLUID TO PRODUCE A PRESSURE PULSE THAT WILL TRAVEL THROUGH THE DRILLING FLUID TO THE SURFACE TO INDICATE THAT THE TWO TELESCOPING SECTIONS OF THE BUMPER SUB ARE IN THE PRESELECTED POSITION. 